Since his birthdate even .357 Magnum (i.e. pre.27) had very often (always maybe) a gap between the shroud and the frame. This is normal and S&W always said it is ok. If you want I can show it on my pre27. And we can not affirm that in that era gunsmiths didn't care about the fitting.
Please take a look here
28-2 ejector shroud gap